The Mammogram DebateFederal health officials are reaffirming the importance of mammograms for women 40 and over. Danish research has raised questions about the value of the preventive exams for breast cancer. NPR's Joanne Silberner reports.

Federal health officials are reaffirming the importance of mammograms for women 40 and over. Danish research has raised questions about the value of the preventive exams for breast cancer. NPR's Joanne Silberner reports.